Media such as CD and DVD discs to which data has been written are used for exchanging data. Data is exchanged using such media instead of paper documents particularly when the volume of data is great.
Media such as CDs on which data has been recorded are produced by media processing devices commonly called CD publishers. The media processing device supplies a blank CD stored in a blank media stacker to a CD drive, writes the data, and then prints on the label side of the CD using a label printer to create the CD. See, for example, Japanese Unexamined Patent Appl. Pub. JP-A-2005-259318.
Conventional media processing devices execute a specific process each time a command is sent from the host computer, and then return a response. When a response from the media processing device is received, the host computer interprets the process result from the response and outputs the next command if the first process is determined to have been executed normally. If the process did not execute normally, the next command is not sent and the process ends. The same operation then repeats, that is, the host computer sends a command to the media processing device, the media processing device executes a specific process according to the received command, and then returns a response to the host computer.
Japanese Unexamined Patent Appl. Pub. JP-A-H07-186462 teaches a recording apparatus that executes a data process according to a command from a host computer. When the data process ends, the recording apparatus executes a termination process and an initialization process. If a communication error occurs while the termination process or initialization process is executing, communication error information is displayed on the operating panel. If there is a status inquiry from the host computer, error information is returned as the response to the host computer.
Japanese Unexamined Patent Appl. Pub. JP-A-H06-135103 teaches a recording apparatus that has a printing control unit and a printing mechanism unit. The printing control unit and the printing mechanism unit exchange commands with each other. When a parameter command is received from the printing control unit, the printing mechanism unit sends a transmission request for one page of data to the printing control unit. When the one page of data is received and the printing process ends, the printing mechanism unit returns a termination signal to the printing control unit. This process repeats for each page. More specifically, every time the printing process for one page of data ends, the printing mechanism unit sends a termination signal informing the printing control unit that printing ended.
Data communication between the host computer and the media processing device is described more specifically with reference to FIG. 11. As shown in the figure, the host computer first sends a command 1 to the media processing device (the actual process being executed by firmware). When the media processing device receives this command 1, the media processing device runs the process corresponding to the command and returns response 1. Command 1 is a command for moving the arm to pick up a blank CD, for example, and when the media processing device receives this command, the media processing device moves the arm to the blank media stacker.
When the host computer receives response 1, it interprets the content and determines if the process corresponding to command 1 executed normally (analysis 1). If the process executed normally, the host computer sends command 2. If the process corresponding to command 1 did not execute normally, the host computer stops the process.
When the media processing device receives command 2, it executes the process corresponding to the command 2 and returns response 2. Command 2 is a blank CD pick-up command, for example, and when this command is received, the media processing device moves the arm to the blank media stacker and picks up one blank CD from the blank media stacker.
When response 2 is received, the host computer interprets the content and determines if the process corresponding to command 2 executed normally (analysis 2). If the process executed normally, the host computer sends command 3. If the process corresponding to command 2 did not execute normally, the host computer stops the process.
The same operation continues to repeat. The host computer thus operates in a send command—receive response—interpret response sequence, and the media processing device operates in a receive command—execute command—send response sequence. This process of returning a response to the host computer each time one command is executed is described, for example, in Japanese Unexamined Patent Appl. Pub. JP-A-2002-279359.
Because the media processing device of the related art thus sends a response to the host computer every time a command is received and the host computer interprets the received content every time a response is received, data traffic is high and the communication processes are frequent, and processing performance between the host computer and the media processing device is not good.